Sustainable electrical energy harvesting via atmospheric water collection using dual-MOF systems

Hydro-electric nanotechnology is touted as a promising next-generation renewable energy system because it employs environmentally-friendly and abundant water as an energy resource for producing electricity efficiently. However, the conventional hydro-electric nanogenerators have some limitations, such as difficulty in continuous and artificial induction of water stream and a low level of energy production for practical use. In this study, we devised a sustainable water harvesting and electrical energy generation system to overcome the limitations of conventional renewable energy . The system was successfully achieved with two distinctive metal-organic frameworks (MOFs), that are, an amine functionalized Zr-based MOF (UiO-66-NH 2 ) particles for atmospheric water harvesting, and a highly conductive Ni 3 (HITP) 2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) MOF-grown cotton-fabric for producing electrical energy. The environmentally responsive UiO-66-NH 2 harvests water from ambient air and the condensed water spontaneously produces electrical potential between wet- and dry-Ni 3 (HITP) 2 , resulting in electrical energy generation with a maximum power and energy densities of 2.6 μW/cm 3 and 1.1 mJ/cm 3 , respectively. Our novel hybrid concept integrating water harvesting and energy generation systems can pave the way for realizing a hydro-electric nanogenerator as a next-generation energy harvesting system in the near future. We proposed the concept of MOF based autonomous water harvesting and sustainable electrical energy generation system by artificial hydrologic cycle. UiO-66-NH 2 and conductive Ni 3 (HITP) 2 MOFs can overcome the limitations of conventional hydro-electric nanogenerators by continuously producing electrical energy from water resources in the air. In the design of autonomous energy generation system maximizes convenience and performance. • Sustainable water harvesting and energy generation system from moisture • Zr 6 O 4 (OH) 4 nodes-based UiO-66-NH 2 MOF efficiently converts water from air • Ni 3 (HITP) 2 conductive MOF has high ion adsorption ability and electrical conductivity • The system continuously produced electricity from air in a real environment